Executive Summary : | In modern day of chemistry, Lewis acids (LAs) or Lewis bases (LBs) which are electron-pair acceptors or donors respectively play an important role. This classic behavior of electron-pair-donor and electron-pair-acceptor molecules was reported by Gilbert N. Lewis in 1923. In general, the Lewis acid (LA) is restricted to trigonal planar geometry with an empty p-orbital which has capability to accept an electron from Lewis base (LB). There are several generalized applications to Lewis acid-base theory such as metals, bifunctional asymmetric catalysts to pharmaceutical synthesis, etc. Stephan and coworkers introduced the concept of “frustrated Lewis pairs” (FLPs) which is a prominent field in main-group chemistry research. The main application of FLP is to activate small molecules. By knowing this kind of interaction in FLP are used to activate small molecules, such as H2, olefins, alkynes, N2O and CO2. Although many FLPs have been reported experimentally and several theoretical studies have also been carried out to address the reaction mechanism, the individual roles of the Lewis acid and base of FLPs still not clear. We propose two steps in order to conduct this systematic investigation to model new LA/LB and frustrated Lewis pair (FLP) by changing the central metal and ligand: i) Attempt to tune the reactivity by changing either the central atom or the ligand attached to the central atom, ii) Design different frustrated Lewis pairs by using superalkalis and superhalogens. The general goal of this proposal is to gain new LA/LB and frustrated Lewis pair (FLP) by changing the central metal and ligand. Particularly, using first principle theory we would like to model Lewis acid (LA) by replacing the ligands by superhalogens (SHs) and using superalkali (SA) as ligand to make more efficient Lewis base (LB) to produce a new class of FLPs. Finally, explore a possible gas sequestration ability with the modeled FLPs and gases like H₂, N₂, CO₂ etc. The density functional theory (DFT) and its complementary analysis like calculation of Vertical Detachment Energy (VDE), Natural bond order (NBO), Dual descriptor and the energy decomposition analysis (EDA-NOCV) will be carried out to provides the theoretical framework for describing the new LA/LB and frustrated Lewis pair (FLP). The results of this project will aid the rational development of new class of FLPs and its potential to act as catalyst and small molecule activator. |